Dana, 1852
Adult members of the decapod Infraorder Caridea are crustaceans with a cylindrical, somewhat laterally compressed or dorso-ventrally compressed carapace. The group consists of the so-called caridian shrimps, to distinguish them from peneaid and sergestid shrimps that belong to the Suborder Dendrobranchiata.
The abdomen is not particularly modified in general shape. The pleural lobe of the second abdominal tergite is markedly enlarged and overlaps the pleural lobes of both the first and third tergite.
The first only, or the first and second pereiopods are chelate (except in the unique genus Procaris, in which no chelation occurs); sometimes the pereiopods lack exopods.
The pleopods and uropods are usually biramous.
The telson forms together with the uropods a tailfan.
Larval development is metamorphic and includes a protozoa, zoa and megalopa.
Ecology
Carideans occur in a wide range of marine, brackish, or freshwater habitats; they may be benthic or pelagic, sometimes commensal with other animals.
Remark
In the present key, adult Caridea are included only in the case of pelagic or benthopelagic species. Larval stages of all caridean species that occur in the North Sea are not keyed out. The following references may be of help in identifying larvae:
Williamson, 1957a (General key); Williamson, 1957b (Family Hippolytidae); Williamson, 1960 (Family Crangonidae); Williamson, 1962 (Family Oplophoridae, Family Nematocarcinidae, Family Pasiphaeidae); Williamson, 1967 (Family Pandalidae, Family Alpheidae); Finchan and Williamson, 1978 (Family Palaemonidae, Family Processidae).
Distribution in the North Sea
Some 50 caridean shrimp species are known from the area, of which only a few are holopelagic; the other are either benthopelagic, in which case they are included in the key, or benthic and not keyed out. The key to pelagic caridean species of the North Sea starts at Page 333: Caridea; those species are listed below in blue.
Explanation of symbols:
k (as prefix) = taxon is keyed-out as adult in the present key
p (as suffix) = adult pelagic
i/h (as suffix) = adult incidentally pelagic, or hyperbenthic
b (as suffix) = adult benthic
k Family Alpheidae
Athanas nitescens(Leach, 1814)p
k Family Crangonidae
k Crangon allmanni Kinahan, 1857i/h
k Crangon crangon (Linnaeus, 1758)i/h
k Philocheras bispinosus (Hailstone, 1835)i/h
k Philocheras echinulatus (Sars, 1861)i/h
Philocheras fasciatus (Risso, 1816)b
Philocheras sculptus (Bell, 1847)b
Philocheras trispinosus (Hailstone, 1835)b
k Pontophilus norvegicus (Sars, 1861)i/h
k Pontophilus spinosus (Leach, 1815)i/h
k Sabinea sarsii Smith, 1879i/h
k Sabinea septemcarinata(Sabine, 1824)i/h
k Family Hippolytidae
k Bythocaris simplicirostris G.O. Sars, 1870i/h
k Caridion gordoni (Bate, 1858)p
k Caridion steveni Lebour, 1930p
Cryptocheles pygmaea Sars, 1870b
k Eualus gaimardii (H. Milne-Edwards, 1837)i/h
Eualus occultus(Lebour, 1936)b
Eualus pusiolus (Krøyer, 1841)b
k Hippolyte varians Leach, 1814i/h
k Lebbeus polaris(Sabine, 1824)i/h
k Spirontocaris lilljeborgii (Danielssen, 1859)i/h
Spirontocaris phippsii (Krøyer, 1841)i/h
k Spirontocaris spinus (Sowerby, 1805)i/h
k Thoralus cranchii (Leach, 1817)i/h
k Family Oplophoridae
k Acanthephyra pelagica(Risso, 1816)p
k Acanthephyra purpureaA. Milne-Edwards, 1881p
k Hymenodora glacialis (Bucholz, 1874)p
k Systellapsis debilis (A. Milne-Edwards, 1881)p
k Family Palaemonidae
k Palaemon adspersus Rathke, 1837i/h
k Palaemon elegans Rathke, 1837i/h
k Palaemon longirostris Milne-Edwards, 1837i/h
k Palaemon serratus (Pennant, 1777)i/h
k Palaemonetes varians (Leach, 1814)i/h
k Family Pandalidae
k Dichelopandalus bonnieri Caullery, 1896i/h
k Pandalina brevirostris (Rathke, 1843)i/h
k Pandalina profundaHolthuis, 1946i/h
k Pandalus borealis Krøyer, 1838i/h
k Pandalus montagui Leach, 1814i/h
k Pandalus propinquus Sars, 1870i/h
k Family Pasiphaeidae
k Parapasiphae cristata S.I. Smith, 1884p
k Parapasiphae sulcatifrons Smith, 1884p
k Pasiphaea multidentataEsmark, 1866p
k Pasiphaea sivado (Risso, 1816)p
k Pasiphaea tarda (Krøyer, 1845)p
Family Processidae
Processa canaliculataLeach, 1815b
Processa edulis (Risso, 1816)b
Processa modica Williamson and Rochanaburanon, 1979b
Processa nouveli Al-Adhub and Williamson, 1975b
Processa parva Holthuis, 1951b
[Description after McLaughlin, 1980; Brusca and Brusca, 1990]